Cryptochrome magnetoreception: four tryptophans could be better than three

Journal of The Royal Society Interface, Год журнала: 2021, Номер 18(184)

Опубликована: Ноя. 1, 2021

The biophysical mechanism of the magnetic compass sensor in migratory songbirds is thought to involve photo-induced radical pairs formed cryptochrome (Cry) flavoproteins located photoreceptor cells eyes. In Cry4a—the most likely six known avian Crys have a sensing function—four pair states are sequentially by stepwise transfer an electron along chain four tryptophan residues photo-excited flavin. purified Cry4a from European robin, third these flavin–tryptophan more magnetically sensitive than fourth, consistent with smaller separation radicals former. Here, we explore idea that two could exist rapid dynamic equilibrium such key and kinetic properties weighted averages. Spin dynamics simulations suggest largely responsible for while fourth may be better placed initiate signalling particularly if terminal can reduced nearby tyrosine. Such arrangement allowed independent optimization essential functions protein. It might also rationalize why has tryptophans plants only three.

Язык: Английский

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Cryptochromes: Photochemical and structural insight into magnetoreception

Protein Science, Год журнала: 2021, Номер 30(8), С. 1521 - 1534

Опубликована: Май 16, 2021

Cryptochromes (CRYs) function as blue light photoreceptors in diverse physiological processes nearly all kingdoms of life. Over the past several decades, they have emerged most likely candidates for light-dependent magnetoreception animals, however, a long history conflicts between vitro photochemistry and vivo behavioral data complicate validation CRYs magnetosensor. In this review, we highlight origins regarding CRY signal transduction, identify recent that provides clarity on potential mechanisms transduction magnetoreception. The review primarily focuses examining differences plant animal CRYs, identifies modes convergent evolution within these independent lineages may conserved signaling pathways.

Язык: Английский

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Computational Reconstruction and Analysis of Structural Models of Avian Cryptochrome 4

The Journal of Physical Chemistry B, Год журнала: 2022, Номер 126(25), С. 4623 - 4635

Опубликована: Июнь 15, 2022

A recent study by Xu et al. (Nature, 2021, 594, 535–540) provided strong evidence that cryptochrome 4 (Cry4) is a key protein to endow migratory birds with the magnetic compass sense. The investigation compared field response of Cry4 from and nonmigratory bird species suggested difference in sensitivity could exist. This finding prompted an in-depth into differences on structural dynamic levels. In present study, pigeon (ClCry4) crystal structure was used reconstruct missing avian structures via homology modeling for carefully selected species. reconstructed European robin, Eurasian blackcap, zebra finch, chicken, were subsequently simulated dynamically analyzed. studied show flexibility analogous regions pointing similar activation mechanisms and/or signaling interaction partners. It can be concluded experimentally recorded different unlikely due solely intrinsic dynamics proteins but requires additional factors have not yet been identified.

Язык: Английский

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Harmonizing Magnetic Mitohormetic Regenerative Strategies: Developmental Implications of a Calcium–Mitochondrial Axis Invoked by Magnetic Field Exposure

Bioengineering, Год журнала: 2023, Номер 10(10), С. 1176 - 1176

Опубликована: Окт. 10, 2023

Mitohormesis is a process whereby mitochondrial stress responses, mediated by reactive oxygen species (ROS), act cumulatively to either instill survival adaptations (low ROS levels) or produce cell damage (high levels). The mitohormetic nature of extremely low-frequency electromagnetic field (ELF-EMF) exposure thus makes it susceptible extraneous influences that also impinge on production and contribute the collective response. Consequently, magnetic stimulation paradigms are prone experimental variability depending diverse circumstances. failure, inability, control for these factors has contributed existing discrepancies between published reports in interpretations made from results generated therein. Confounding environmental include ambient fields, temperature, mechanical environment, conventional use aminoglycoside antibiotics. Biological type seeding density as well developmental, inflammatory, senescence statuses cells depend prior handling sample. Technological aspects directionality, uniformity, amplitude, duration exposure. All will exhibit manifestations at level culminate unified cellular response conjunction with Fortunately, many under experimenter. This review focus delineating areas requiring technical biological harmonization assist designing therapeutic strategies more clearly defined better predicted outcomes improve mechanistic interpretation data, rather than precise applications. explore underlying similarities other forms biophysical stimuli, such mutually induce elevations intracellular calcium prerequisite outcome. These stimuli commonly invoke activity transient receptor potential cation channel classes, TRPC1.

Язык: Английский

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Singlet–triplet dephasing in radical pairs in avian cryptochromes leads to time-dependent magnetic field effects

The Journal of Chemical Physics, Год журнала: 2023, Номер 159(10)

Опубликована: Сен. 11, 2023

Cryptochrome 4a (Cry4a) has been proposed as the sensor at heart of magnetic compass in migratory songbirds. Blue-light excitation this protein produces magnetically sensitive flavin-tryptophan radical pairs whose properties suggest that Cry4a could indeed be suitable a magnetoreceptor. Here, we use cavity ring-down spectroscopy to measure field effects on kinetics these modified proteins from European robin and nonmigratory pigeon chicken. B1/2, parameter characterizes field-dependence reactions, was found larger than expected basis hyperfine interactions increase with delay between pump probe laser pulses. Semiclassical spin dynamics simulations show behavior is consistent singlet-triplet dephasing (STD) relaxation mechanism. Analysis experimental data gives rate constants, rSTD, range 3-6 × 107 s-1. A simple "toy" model due Maeda, Miura, Arai [Mol. Phys. 104, 1779-1788 (2006)] used shed light origin time-dependence nature STD Under conditions experiments, results an exponential approach equilibrium considerably slower rSTD. We attribute loss coherence electron hopping second third tryptophans transfer chain comment whether process explain differences sensitivity robin, chicken, Cry4a's.

Язык: Английский

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Orientation of birds in radiofrequency fields in the absence of the Earth’s magnetic field: a possible test for the radical pair mechanism of magnetoreception

Journal of The Royal Society Interface, Год журнала: 2024, Номер 21(217)

Опубликована: Авг. 1, 2024

The magnetic compass sense of migratory songbirds is thought to derive from magnetically sensitive photochemical reactions in cryptochromes located photoreceptor cells the birds’ retinas. More specifically, transient radical pairs formed by light-activation these proteins have been proposed account for ability orient themselves using Earth’s field and observation that radiofrequency fields, superimposed on field, can disrupt this ability. Here, means spin dynamics simulations, we show it may be possible birds a monochromatic absence field. If such behavioural test were successful, would provide powerful additional evidence pair mechanism avian magnetoreception.

Язык: Английский

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Flavin Adenine Dinucleotide (FAD) as a Non-Canonical RNA Cap: Mechanisms, Functions, and Emerging Insights

Archives of Biochemistry and Biophysics, Год журнала: 2025, Номер 766, С. 110326 - 110326

Опубликована: Фев. 5, 2025

Язык: Английский

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Effects of Light Conditions on the Leaf Growth and Steviol Glycoside Yields of Hydroponically Cultivated Stevia Across Growth Stages

Horticulturae, Год журнала: 2025, Номер 11(3), С. 316 - 316

Опубликована: Март 13, 2025

Extracts of Stevia rebaudiana are rich in sweet-tasting steviol glycosides (SG), which widely valued as natural sweeteners. This study investigated the effects different light conditions on stevia growth and SG production across stages using a controlled hydroponic system. Four were introduced at low photosynthetic photon flux density 50 μmol·m−2·s−1. was divided into four stages, leaf weight yield analyzed. Red resulted highest fresh weights 23.53 g·plant−1, whereas green lowest 17.15 marking difference 37.2%. However, performed total content (LSG) 190.68 mg·g−1 (YSG) 39.24 g·m−2, compared to LSG under red 108.68 YSG 24.76 derived differences 75.45% 58.48%, respectively. These results suggest trade-off between vegetative synthesis. is optimal for early-stage biomass accumulation, while blue treatments during last two respectively, may enhance overall production. Consequently, offered insights commercial cultivation SG.

Язык: Английский

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Structural Plasticity and Functional Dynamics of Pigeon Cryptochrome 4 as Avian Magnetoreceptor

Journal of Molecular Biology, Год журнала: 2025, Номер unknown, С. 169233 - 169233

Опубликована: Май 1, 2025

Язык: Английский

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Decrypting the Nonadiabatic Photoinduced Electron Transfer Mechanism in Light-Sensing Cryptochrome

ACS Central Science, Год журнала: 2025, Номер unknown

Опубликована: Май 30, 2025

Язык: Английский

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